Microelectromechanical transducers play a central role in modern electronics both as sensors and also as actuators and are used in a multiplicity of different applications, for example as microphones, loudspeakers, pressure sensors or acceleration sensors.
Microelectromechanical transducers can have a membrane, which can be displaced in a passive or active manner depending on whether the transducers are formed as sensors or actuators. In the case of a microelectromechanical transducer formed as a sensor, the membrane can be displaceable in a passive manner, for example by sound to be detected or an acceleration to be detected. Characteristics of the variable to be detected, such as a sound frequency, a sound amplitude or a temporal acceleration profile, can be ascertained from a displacement of the membrane. In the case of a microelectromechanical transducer formed as an actuator, the membrane can be displaced in an active manner, for example in order to generate sound in a loudspeaker.
Such membranes of microelectromechanical transducers can be formed at least in sections from a piezoelectric material, in which, in the case of a passive displacement of the membrane, a voltage is induced, which can be read out by a suitable read-out circuit in order to ascertain characteristics of a variable to be detected. Alternatively, in the case of an actuator, a voltage can be applied to the membrane in order to bring about a targeted deformation of the membrane, for example in order to generate sound.